Manufacture of textile threads and fabrics



Patented Aug. 10, 1937 MANUFACTURE OF TEXTILE THREADS AND FABRICS Henry Dreyfus, London, England No Drawing. Application March 14, 1935, Se-

rial No. 11,078. In Great BritainMal-ch 21,

9 Claims. (01. 117-2} This invention relates to the manufacture of crepe threads of cellulose acetate or other cellulose ester or ether, and to the production of fabrics therefrom.

5 Inthe past, great difiicultyhas been experienced in producing, with the aid of, cellulose ester or ether threads to which a crepe twist has been imparted, fabrics exhibiting crpe effects of the kind readily obtainable by weaving a fabric from highly twisted yarns of natural, silk in the gummed state and subjecting the fabric to a hot aqueous treatment. Generally, substantially no crpe eifect is obtainable by simply applying to cellulose acetate thread a twist of the order of 15 that commonly employed in connection with natural silk crepe threads, weaving the twisted threads into a fabric and subjecting the latter to a hot aqueous treatment.

In accordance with the present invention in applying a crpe twist to threads of cellulose acetate or other cellulose esters or ethers at least the last part of the crpe twist is applied whilst the material of the thread is ina softened state. In

this way it is possible to produce celluloseQacetate or other cellulose ester or ether 'crpe threads having, as compared with threadsproduced by a 7 simple twisting operation, greatly improved properties, particularly as regards strength and the ability to yield fabrics exhibiting vgood crepe an The softening of the material of the threads may advantageously be efiected by subjecting the threads to the action of softening agencies dur ing the actual application of crpe twist.- Thus the thread may be twisted'on a device of the kind in which thethread is drawnofi over the end of a rotating package and allowed to pass, on its way to a'winding device, through a body of aliquid softening agent. I I .m The agencies contemplated for. use in accordance with the present invention are more partic-' ularly those which have a mild softening or plasticizing effect on the material ofthe filaments, and particularly such agencies thesoftening 4:, effect of which may rapidly and completely be dispelled when they have served their purpose. As examples of agents which may be employed to eilect the desired temporary softening or plasticizing of the filaments in accordance with the 50 present invention, mention may be made of those organic liquids which have a mild softening action on cellulose esters or ethers, particularly a softening action of the order'of that of boiling water on cellulose acetate. Volatile organic liquids are 55 convenient in that materials softened by them may quickly and easily be restored to their orig-. inal condition by volatilization of the liquid. In the case of treating cellulose esters, mention may be made of the following as examples of liquids which may be usedto effect the softening of the cellulose ester:aliphatic hydrocarbons, for example low-boilin'g fractions of petroleum, or aromatic hydrocarbons, for example .benzene, toluene,. xylenes, or mixtures of these hydrocarbons; aliphatic alcohols for example methyl or 10 ethyl alcohol, or higher alcohols, e. g. propyl, butyl or amyl alcohols, or glycol, glycerol or other dior poly-hydric alcohols; ethers, for example dialkyl ethers, e. g. di-isopropyl ether and mono-, di-, or poly-ethers of glycol, glycerol or other dior poly-hydric alcohols. Again, esters may be used c. g. ethyl acetate, ethyl lactate, or ethyloxy-butyrate. Substances of high swelling or solvent action on the material of the threads may be diluted with substances of low swelling action, e. g. hydrocarbons.

Instead of employing organic liquids as softening agents, aqueous liquids containing substanceswhich impart to the aqueous liquid a softening or swelling action on cellulose esters or ethers,-may be employed; Thus, aqueous solutions of organic solvents or swelling agents for cellulose esters or ethers may be used, the concentration of the organic substance being adjusted according to the precise degree of softening power required. For example, aqueous solutions of phenol, acetone, pyridine, alcohol, glycol, ethers or esters of glycol, e. g. monoethyl-ether of ethylene glycol, may be used. Again, aqueous solutions of inorganic agents having a solvent or, swelling 'action on cellulose esters or ethers may be employed, forexample aqueous solutions of thiocyanates.

l The aqueous or other liquids employed may be 40 used either hot or cold, according to their softening action on the cellulose esters or'ethers, and according to the precise degree of softening reguired. In general, it is advantageous. to employ liquids having the desired softening or plasticizing action when hot, but little or no softening or plasticizing action when cold, e. g. glycol or glycer'ol. By the use of such liquids the desired transient softening of the material of the filaments may readily'be secured.

The liquid softening agent may be employed under pressure, for example pressures of a few pounds per square inch or pressures of several atmospheres.

Liquid aqueous softening agents may contain 5 Still another method of effecting the desired temporary softening or plasticizing of the material of the filaments is to utilize the vapors of organic substances and especially of such organic substances as do not have a strong solvent or softening action on the materials. The vapors may be saturated or superheated or employed in the presence of the substance in liquid form. As examples of suitable vapors may be mentioned those of aliphatic alcohols, e. g. methyl, ethyl, propyl, butyl or amyl alcohol, and those of aliphatic or aromatic hydrocarbons or of certain halogenated organic compounds, for example carbon tetrachloride, or mixtures thereof. The vapors may be employed at atmospheric pressure or at pressures below or above atmospheric pressure, for example at 5 to 20 lbs. per square inch or more above atmospheric pressure.

Steam may be used in conjunction with the softening agents if desired. Thus threads containing or moistened with softening agents may be subjected to the action of steam during twisting. Again;.softening may be effected with the aid of a mixture of steam and the vapor of an organic softening agent.

If desired, the requisite softening of the material of the filaments may be effected by means of heat and without the use of a substance which itself has a softening action on the material of the filaments. Thus, the softening may be effected by means of a heated gas, or by means ,of a superheated vapor.

i In carrying out the new process, twisting is most advantageously effected on a device of the kind in which the thread is drawn off over the end of a rotating package through a guide fixed substantially in line with the axis of rotation of the pack- 40 age and is thereafter wound on a bobbin or the like; the thread being softened on its way from the guide to the bobbin. In this way the thread is in a softened state during the actual application of twist. 45 On the other hand, any other suitable crpe twisting device may be employed. For example a ring twister may be used.

The twisting spindle, the guide fixed in line with the axis of the spindle, and the means for 50 softening the thread; should be so arranged that the twist resulting from the rotation of the package is at least partly inserted while the thread is in a softened state. If the freedom of the I thread to rotate within the balloon guide or 5 other guide preceding or forming part of the liquid treatment device is unduly restricted, e. g. by causing the thread to change direction materially at the guides, the insertion of twist while the thread is in a softened state may be restricted 60 to an undesirable extent or substantially prevented and the resulting crpe threads may not have the valuableproperties which may otherwise be secured. Using a twisting device of the kind in which thread is drawn off over the end 65 of a rotating package, it is advantageous to arrange that the path of the thread after leaving the balloon guide=and through the zone in which softening is effected, is substantially in line with the axis of the spindle.

7 If desired, the above-mentioned twisting devices, in which the thread is drawn of! over the end of a rotating package, may be provided with a device which restricts the ballooning of the thread or the tendency of twist to run back to the pack- 75 age. As examples of such devices may be mentioned flyers and the floating ring device described in U. S. Patent No. 1,784,581. The latter device is of particular value when the thread to be twisted is of very low twist, for example less than about 1 turn per inch.

The treatment of the.thread with a liquid softening agent during twisting may be effected by drawing the thread off from a twisting spindle and passing it upwardly through a small hole in a suitable receptacle containing the liquid, the thread then passing to a winding device. The hole may be, for example, about of an inch in diameter and may be provided with means adapted to lead away and prevent from reaching the twisting spindle, any liquid issuing from the hole. If desired, the hole may take the form of a short tube of fine bore, fixed in the receptacle, whereby the flow of liquid from the receptacle at the point of entrance of the threadmay be reduced. Another method is to supply the liquid to the thread. For example, the thread may be causedto pass in contact with a wick dipping into the liquid or in contact with a horizontally disposed roller, preferably circumferentially grooved, arranged to rotate in a bath of the liquid and so to carry it to the thread. In the case of using hot liquids the liquid maybe supplied to the thread in a heated state or it may be applied to the thread at a lower temperature and the thread then heated, e. g. by passing it through a heated chamber on its way to the winding device.

The zone in which the thread is in a softened state may be relatively short, for example 1 to 3 inches.

In the case of using' vapors to effect the desired softening the thread may be drawn off from a twisting spindle and passed through a suitable vided with inlet and outlet holes for the thread Such an apparatus may con of each spindle. veniently consist of a horizontal pipe mounted over a row of spindles and provided with eyes'of porcelain, stainless steel, or other suitable material at appropriate points on top and bottom for the entrance and exit of the threads. The diameter of the pipe is sufficient to afford the thread the'requisite length of travel in the vapor. Vapor may be admitted to the pipe at one point or at more than one point as may be necessary according to the length of the pipe, to secure sufficiently uniform conditions of steaming as between the threads from the difierent' spindles.

If desired vapors of the softening agents may be employed in the presence of a liquid softening agent., The presence of liquid softening agent may be assured by arranging for condensation of the vapor in the vapor treating device. Another method of ensuring the presence of liquid softening agent is to moisten the thread therewith; for example the liquid may be applied to the thread by means of a wick or other device after the thread leaves the spindle and prior to its entering the vapor treatment device.

If desired a softening agent may be incorporated in the threads in an operation separate from the' crepe twisting operation. Thus, packages of threads may be impregnated with an appropriate softening agent and thereafter crepe twisted; For example, the threads in package form may be subjected to the action of vapor of a solvent or they may be dipped into a liquid softening agent. Softening agents of high boiling point may be applied in solution in a volatile'liquid, e. g. benzene or petrol, and if desired the latter removed by evaporation In the case of volatile softening agents it is preferable, in order to avoid loss of volatile softening agent, to twist on a deviceof the kind in which the thread is drawn off from a stationary or slowly rotating package and twisted as it is wound on to a second package.

Again, if desired, cellulose ester and ether threadsmay be twisted-immediately after their formation-by dry or wet spinning methods and while they still contain a solvent ona constituent of a spinning bath of such nature and in such proportion as .to afiord the-desired degree of softness. For example, cellulose acetate threads con-' ning eifected at comparatively low temperatures in order to leave the desired proportion of softening agent in the filaments. Again, there may be added to the Spinning solution substances which retard the evaporation of solvent. Qetyl alcohol and other alcohols, for example in amounts of 10-20% of the weightof the cellulose ester or ether may be used for this purpose.

' The initial thread may'already be twisted to a small degree, for example up to, 10 turns per inch,

e. g. to 2 to 5 turns per inch or to such small degree as is commonly applied in the production of cellulose acetate threads by dry spinning cellulose acetate solutions and winding and twisting the resultant filaments on a cap twisting device.

In carrying out the new process the crpe twist may be applied in a single stage. If desired, however, the twist may be applied in two or more stages, the final stage of twisting being efiected whilst the material of the thread is in a softened state.

When the crepe twistis applied in two or more .stages the advantages of the process may be obtained when not only the final stage of the crepe twisting but an earlier stage or stages of twisting are also efiected whilst the material of the thread is in a softened, state. In fact it is of great advantage to effect, while the material of the thread is in a softened state, any application of. twist beyond the point at which twisting would result in weakening of the thread if the said twisting were efiected while the material of the thread was not in ,the softened state.

The precise-degree of twist beyond which it is important that the material of the thread should be in a softened state during twisting depends upon the total denier of the thread and the number of its constituent filaments. Generally at least the last two-thirds of the total crepe twist should be applied whilst the material of the thread is in a softened state. I

The cellulose ester or ether filaments of the threads very readily undergo stretching when the threads are twisted while in a softened state. The amount of stretch may be measured by comparing the original thread denier with the final thread denier (after untwisting). It has been found that when a cellulose ester or ether thread is crpe twisted while in a softened state so as to produce a crepe thread of good strength and crping properties, the denier of the resultant thread is, in general, owing to imparted stretch, less and even substantially less than if the thread is simply crepe twisted in the ordinary manner.

The stretch imparted to the filaments of the threads during the twisting operation may for example be of the order of 5-25% of their original length, and particularly '10-20%. The degree of stretching of the filaments of the thread may be such that the final d'enier of the crepe twisted thread is not much in excess of or is even the same or less than the denier .of the thread prior to twisting. For example the stretch may be such that the denier of the crepe twisted thread is from 95 to 115%, particularly 100 to'110% of that of the thread .before crepe twisting, especially 'in the ease of threads having an original denier of 150 or less. Good crepe fabrics may however be obtained when the final denier is still greater, for example up to 120% of that of the thread beforetwisting when threads having a denier about 200 are employed.

The degree of twist applied in accordance with the new process may vary within wide limits. A feature of the process is that it enables a high degree of twist to be applied without such a great weakening of the thread as is almost invariably experienced when cellulose ester or ether crepe threads are prepared by ordinary methods of crepe twisting. The process, moreover, permits the insertion of twists which are impossible of attainment when the thread is not in the softened state. This is important since it enables crepe fabrics to be produced having very pronounced. crepe efiects. The crepe figure can be regulate according to requirements. desirable in any particular case depends upon the denier of the thread. For example with threads of 165 denier twist of about 70 to 75 turns per inch is desirable, and with threads of 115 denier twist of about 85 to 90 turns per inch. With these indications it is a simple matter to determine the desirable twists for threads of other deniers. the threads after crepe twisting.

The denier numbers given are those of As indicated above, the new process enables of at least some of the filaments has occurred during the process of twisting. The filaments of the thread, however, are not stuck together and can be separated upon untwisting. Moreover,

the new cellulose ester or etherr'crpe threads are smooth. and cylindrical as opposed to the rough feel and helical form of a cellulose ester or ether thread or a viscose thread which has been crepe twisted in the ordinary way. Further, in comparison with theselatter threads, the smooth cylindrical cellulose ester or ether crepe threads The degree of twist exhibit much less tendency to snarl or kink.

These characteristics distinguish the new cellulose ester or ether crepe threads.

The invention is of particular value in connection with the production of crepe threads of filaments of cellulose acetate. Crepe threads of filaments of other cellulose esters or cellulose ethers may, however, be produced by the new method.

As examples of cellulose esters of which the filaments of the crepe threads may be made, mention may be made of nitrocellulose or of organic esters of cellulose, for example cellulose formate, cellulose propionate or cellulose butyrate. If desired, the filaments may be made of mixed esters of cellulose, for example cellulose nitroacetate or cellulose acetate-butyrate. Methyl cellulose, ethyl cellulose and benzyl cellulose are examples of cellulose ethers of which the threads may be made. Again, if desired, filaments made'of etheresters of cellulose may be employed, for example filaments of a low ether cellulose which has been acetylated or otherwiseesterified, or filaments of an esterifie'd (hydroxy-alkyl) -ether of cellulose, e. g. acetylated (hydroxy-ethyl),-cellulose. The crepe threads may be made with filaments such as have been prepared by extruding into a coagulating medium a solution of the cellulose ester or ether in a suitable solvent. Again, they may be such as have been prepared by ester iflca-- .39 tion of cellulose filaments without losing the filamentary form of the latter, e. g. filaments pf regenerated cellulose which have been esterified-bymeans of acetic anhydride, butyric anhydride or r other esterifying agent. 1 The threads may contain substantially continuous filaments of cellulose esters or ethers or they may contain discontinuous filaments of the esters or ethers,'the length of which may vary within wide limits- For example the threads may be those spun from a mass of discontinuous filaments or those prepared in the manner described in British Patents Nos. 424,683, 424,752, 424,830' and 424,879.

If desired there may be employed threads-consisting of on containing cellulose ester filaments which have been superficially saponified or have been partially saponified throughout. The saponification may b'eeflected intermittently along the lengthof the threads. The invention is of particular advantage in connection with the production of crepe threads consisting wholly of cellulose acetate or other cellulose ester or ether filaments. If desired,

however, the threads may be composed in part of filaments of one ester or ether of cellulose and in part of filaments of another ester or ether of cellulose, or in part of filaments of a cellulose ester or ether-and in part of filaments of another material, for example natural silk or regenerated cellulose. As in the case of the cellulose ester or ether' filaments, such other filaments may be substantially continuous filaments and/or discontinuous filaments.

While the new process enables production of threads which yield satisfactory crepe effects without a special treatment, other than the twisting and softening treatment characteristic of the process, other devices-and treatment may, if desired, be employed further to improve the properties of the crepe threadsand/or fabrics produced therefrom. For example, the twist may be irregular in character as-described in British Patent No. 385,585. Further, the crepe threads may be sized, uniformly or intermittent- 1y along their length at any suitable stage of their manufacture, for example prior to; the application of twist, or at least any substantial proportion of the twist. In this connection, particular mention may be made of sizing materials selected in accordance with the consid- 5 erations laid down in U. S. Patent No. 2,007,182. For example a casein, egg-albumen -or other size which is not very readily removed by aqueous treatments may be employed. Another size which may be employed is a drying oil, if de- 10 sired one which has been partially oxidized, e. g. boiled or blown linseed oil. Hygroscopic substances, for example sodium acetate, calcium chloride, calcium nitrate, citric acid, glycerine, sodium lactate etc., may be incorporated in the 15 materials prior to the crepe twisting, for example, in the case of threads of extruded filaments, by way of the spinning solutions from which the threads are prepared. In such a case the threads may already contain sumcient 20 moisture to give the desired softening so that either at ordinary temperatures or at suitably raised temperatures, produced for example by the simple application of hot air, dry steam or the like, the improved crpe twisting is obtained. 25 Another treatment which is sometimes found beneficial is a wetting treatment. Such wetting may be effected, for instance, before or during the application of the crepe twist. Thus, the

thread may be wetted as it leaves a twisting 30' -of threads of right-hand twist.

Fabrics containing highly twisted crepe threads prepared in accordance with the inventionmay 45 subsequently be subjected to a hot aqueous treatment, for example in the manner commonly adopted in connection with; fabrics comprise 'ing-highly twisted crepe threads of natural silkl Such treatment may be, for instance, a. treat- 50 ment in an aqueous soap bath at a temperature of '75-85 C. or at higher temperatures, e.-g. at the boil. If desired the fabrics or the threads from which they are prepared may be treated, prior to the hot aqueous treatment, so 55 as to remove wholly or in part any softening agent, such removal may be effected for. example by heating or by washing with a suitable liquid,

e. g. benzene. I

Fabrics containing highly twisted threads 60 prepared in accordance with the invention may also be subjected to a treatment adapted to swell the material of the filaments of the said threads. Such treatment may be in addition to the hot aqueous treatment of the woven fabric, 65 and may be effected before or after, or simultaneously with, the said hot aqueous treatments. The term organic derivative of cellulose used in the appendant claims connotes a cellulose ester of an organic acid or a cellulose ether. ,70

What I claim and desire to secure by Letters Patent is:-- 1. Process for the production of highly twisted cellulose acetate crepe threads, which comprisescrepe twisting cellulose acetate threads and, dur- 75 ing the insertion of at least the last part of the crepe twist, treating the threads with an organic softening agent therefor'so that during twisting the filaments of the threads are so softened and stretched that the final thread denier is less than 115% of that of the thread before crepe twisting.

2. Process for the production of highly twisted cellulose acetate crepe threads, which comprises crepe twisting cellulose acetate threads which, during the insertion of at least the last part of the crepe twist, are so soft under the action of an organic softening agent that during twisting the filaments of the threads become so closely packed together, that the apparent specific gravity of the threads is at least 85% of that of the material of the filaments.

3. Process for the production of highly twisted cellulose acetate crepe threads, which comprises applying to a cellulose acetate thread a minimum crepe twist determined according to the denier, the said minimum being 70 turns per inch for thread of 165 denier and 85 turns per inch for thread of 115 denier, and softening the thread with an organic softening agent during the insertion of at least the last part of the twist so that the filaments of the thread stretch so much that the denier of the final thread is less than 115% of that of the thread before twisting.

4. Process for the production of highly twisted cellulose acetate crepe threads, which comprises crepe twisting cellulose acetate threads in at least two stages, and during the final stage of twisting treating the threads with an organic softening agent therefor, so that the material of the threads is softened to such a degree that the filaments undergo substantial stretching during the twistmg.

5. Process for the production of highly twisted cellulose acetate crepethreads, which comprises crepe twisting cellulose acetate threadsand, during the insertion of at least the last part of the crepe twist, treating the threads with an organic softening agent therefor so that during twisting the filaments of the threads are so softened and stretched that the final thread denier is less than 120% of that of the thread before crepe twisting.

6. Process for the production of highly twisted cellulose acetate crepe threads, which comprises crepe twisting cellulose acetate threads and, during the insertion of at least the last part of the crepe twist, treating the threads with an organic liquid softening agent therefor so thatv during twisting the filaments of the threads are so softened and stretched that the final thread denier is less than 115% of that of the thread before crepe twisting.

7. Process for 'the production of highly twisted crepe threads of an organic derivative of cellulose, which comprises crepe twisting threads of an organic derivative of cellulose and, during the insertion of at least the last part of the crepe twist, treating the threads with an organic softening agent therefor so that during twisting the fila-. I ments of the threads are so softened and stretched that the final thread denier is less than 115% of that of the thread before crepe twisting.

8. Process for the production of highly twisted crepe threads of an organic derivative of cellulose, which comprises crepe twisting threads of an organic derivative of cellulose in at least two stages, and during the final stage of twisting treating the threads with an organic softening agent therefor, so that the material of the threads is softened to such a degree that the filaments undergo substantial stretching during the twisting.

9. Process for the production of highly twisted crepe threads of an organic derivative of cellulose, which comprises crepe twisting threads of an organic derivative of cellulose and, during the insertion of at least the last part of the crepe twist,

treating the threads wtih an organic softening agent therefor so that during twisting the fila ments of the threads are so softened and stretched that the final thread denier is less than of that of the thread before'crepe twisting.

HENRY DREYFUS. 

